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40819f6f GF |
1 | #include "ceph_debug.h" |
2 | ||
3 | #include <linux/file.h> | |
4 | #include <linux/namei.h> | |
5 | ||
6 | #include "super.h" | |
7 | #include "mds_client.h" | |
8 | #include "pagelist.h" | |
9 | ||
10 | /** | |
11 | * Implement fcntl and flock locking functions. | |
12 | */ | |
13 | static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file, | |
14 | u64 pid, u64 pid_ns, | |
15 | int cmd, u64 start, u64 length, u8 wait) | |
16 | { | |
17 | struct inode *inode = file->f_dentry->d_inode; | |
18 | struct ceph_mds_client *mdsc = | |
19 | &ceph_sb_to_client(inode->i_sb)->mdsc; | |
20 | struct ceph_mds_request *req; | |
21 | int err; | |
22 | ||
23 | req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); | |
24 | if (IS_ERR(req)) | |
25 | return PTR_ERR(req); | |
26 | req->r_inode = igrab(inode); | |
27 | ||
28 | dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " | |
29 | "length: %llu, wait: %d, type`: %d", (int)lock_type, | |
30 | (int)operation, pid, start, length, wait, cmd); | |
31 | ||
32 | req->r_args.filelock_change.rule = lock_type; | |
33 | req->r_args.filelock_change.type = cmd; | |
34 | req->r_args.filelock_change.pid = cpu_to_le64(pid); | |
35 | /* This should be adjusted, but I'm not sure if | |
36 | namespaces actually get id numbers*/ | |
37 | req->r_args.filelock_change.pid_namespace = | |
38 | cpu_to_le64((u64)pid_ns); | |
39 | req->r_args.filelock_change.start = cpu_to_le64(start); | |
40 | req->r_args.filelock_change.length = cpu_to_le64(length); | |
41 | req->r_args.filelock_change.wait = wait; | |
42 | ||
43 | err = ceph_mdsc_do_request(mdsc, inode, req); | |
44 | ceph_mdsc_put_request(req); | |
45 | dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " | |
46 | "length: %llu, wait: %d, type`: %d err code %d", (int)lock_type, | |
47 | (int)operation, pid, start, length, wait, cmd, err); | |
48 | return err; | |
49 | } | |
50 | ||
51 | /** | |
52 | * Attempt to set an fcntl lock. | |
53 | * For now, this just goes away to the server. Later it may be more awesome. | |
54 | */ | |
55 | int ceph_lock(struct file *file, int cmd, struct file_lock *fl) | |
56 | { | |
57 | u64 length; | |
58 | u8 lock_cmd; | |
59 | int err; | |
60 | u8 wait = 0; | |
61 | u16 op = CEPH_MDS_OP_SETFILELOCK; | |
62 | ||
63 | fl->fl_nspid = get_pid(task_tgid(current)); | |
64 | dout("ceph_lock, fl_pid:%d", fl->fl_pid); | |
65 | ||
66 | /* set wait bit as appropriate, then make command as Ceph expects it*/ | |
67 | if (F_SETLKW == cmd) | |
68 | wait = 1; | |
69 | if (F_GETLK == cmd) | |
70 | op = CEPH_MDS_OP_GETFILELOCK; | |
71 | ||
72 | if (F_RDLCK == fl->fl_type) | |
73 | lock_cmd = CEPH_LOCK_SHARED; | |
74 | else if (F_WRLCK == fl->fl_type) | |
75 | lock_cmd = CEPH_LOCK_EXCL; | |
76 | else | |
77 | lock_cmd = CEPH_LOCK_UNLOCK; | |
78 | ||
79 | if (LLONG_MAX == fl->fl_end) | |
80 | length = 0; | |
81 | else | |
82 | length = fl->fl_end - fl->fl_start + 1; | |
83 | ||
84 | err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file, | |
85 | (u64)fl->fl_pid, (u64)fl->fl_nspid, | |
86 | lock_cmd, fl->fl_start, | |
87 | length, wait); | |
88 | if (!err) { | |
89 | dout("mds locked, locking locally"); | |
90 | err = posix_lock_file(file, fl, NULL); | |
91 | if (err && (CEPH_MDS_OP_SETFILELOCK == op)) { | |
92 | /* undo! This should only happen if the kernel detects | |
93 | * local deadlock. */ | |
94 | ceph_lock_message(CEPH_LOCK_FCNTL, op, file, | |
95 | (u64)fl->fl_pid, (u64)fl->fl_nspid, | |
96 | CEPH_LOCK_UNLOCK, fl->fl_start, | |
97 | length, 0); | |
98 | dout("got %d on posix_lock_file, undid lock", err); | |
99 | } | |
100 | } else { | |
101 | dout("mds returned error code %d", err); | |
102 | } | |
103 | return err; | |
104 | } | |
105 | ||
106 | int ceph_flock(struct file *file, int cmd, struct file_lock *fl) | |
107 | { | |
108 | u64 length; | |
109 | u8 lock_cmd; | |
110 | int err; | |
111 | u8 wait = 1; | |
112 | ||
113 | fl->fl_nspid = get_pid(task_tgid(current)); | |
114 | dout("ceph_flock, fl_pid:%d", fl->fl_pid); | |
115 | ||
116 | /* set wait bit, then clear it out of cmd*/ | |
117 | if (cmd & LOCK_NB) | |
118 | wait = 0; | |
119 | cmd = cmd & (LOCK_SH | LOCK_EX | LOCK_UN); | |
120 | /* set command sequence that Ceph wants to see: | |
121 | shared lock, exclusive lock, or unlock */ | |
122 | if (LOCK_SH == cmd) | |
123 | lock_cmd = CEPH_LOCK_SHARED; | |
124 | else if (LOCK_EX == cmd) | |
125 | lock_cmd = CEPH_LOCK_EXCL; | |
126 | else | |
127 | lock_cmd = CEPH_LOCK_UNLOCK; | |
128 | /* mds requires start and length rather than start and end */ | |
129 | if (LLONG_MAX == fl->fl_end) | |
130 | length = 0; | |
131 | else | |
132 | length = fl->fl_end - fl->fl_start + 1; | |
133 | ||
134 | err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, | |
135 | file, (u64)fl->fl_pid, (u64)fl->fl_nspid, | |
136 | lock_cmd, fl->fl_start, | |
137 | length, wait); | |
138 | if (!err) { | |
139 | err = flock_lock_file_wait(file, fl); | |
140 | if (err) { | |
141 | ceph_lock_message(CEPH_LOCK_FLOCK, | |
142 | CEPH_MDS_OP_SETFILELOCK, | |
143 | file, (u64)fl->fl_pid, | |
144 | (u64)fl->fl_nspid, | |
145 | CEPH_LOCK_UNLOCK, fl->fl_start, | |
146 | length, 0); | |
147 | dout("got %d on flock_lock_file_wait, undid lock", err); | |
148 | } | |
149 | } else { | |
150 | dout("mds error code %d", err); | |
151 | } | |
152 | return err; | |
153 | } | |
154 | ||
155 | /** | |
156 | * Must be called with BKL already held. Fills in the passed | |
157 | * counter variables, so you can prepare pagelist metadata before calling | |
158 | * ceph_encode_locks. | |
159 | */ | |
160 | void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) | |
161 | { | |
162 | struct file_lock *lock; | |
163 | ||
164 | *fcntl_count = 0; | |
165 | *flock_count = 0; | |
166 | ||
167 | for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { | |
168 | if (lock->fl_flags & FL_POSIX) | |
169 | ++(*fcntl_count); | |
170 | else if (lock->fl_flags & FL_FLOCK) | |
171 | ++(*flock_count); | |
172 | } | |
173 | dout("counted %d flock locks and %d fcntl locks", | |
174 | *flock_count, *fcntl_count); | |
175 | } | |
176 | ||
177 | /** | |
178 | * Encode the flock and fcntl locks for the given inode into the pagelist. | |
179 | * Format is: #fcntl locks, sequential fcntl locks, #flock locks, | |
180 | * sequential flock locks. | |
181 | * Must be called with BLK already held, and the lock numbers should have | |
182 | * been gathered under the same lock holding window. | |
183 | */ | |
184 | int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist, | |
185 | int num_fcntl_locks, int num_flock_locks) | |
186 | { | |
187 | struct file_lock *lock; | |
188 | struct ceph_filelock cephlock; | |
189 | int err = 0; | |
190 | ||
191 | dout("encoding %d flock and %d fcntl locks", num_flock_locks, | |
192 | num_fcntl_locks); | |
193 | err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32)); | |
194 | if (err) | |
195 | goto fail; | |
196 | for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { | |
197 | if (lock->fl_flags & FL_POSIX) { | |
198 | err = lock_to_ceph_filelock(lock, &cephlock); | |
199 | if (err) | |
200 | goto fail; | |
201 | err = ceph_pagelist_append(pagelist, &cephlock, | |
202 | sizeof(struct ceph_filelock)); | |
203 | } | |
204 | if (err) | |
205 | goto fail; | |
206 | } | |
207 | ||
208 | err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32)); | |
209 | if (err) | |
210 | goto fail; | |
211 | for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { | |
212 | if (lock->fl_flags & FL_FLOCK) { | |
213 | err = lock_to_ceph_filelock(lock, &cephlock); | |
214 | if (err) | |
215 | goto fail; | |
216 | err = ceph_pagelist_append(pagelist, &cephlock, | |
217 | sizeof(struct ceph_filelock)); | |
218 | } | |
219 | if (err) | |
220 | goto fail; | |
221 | } | |
222 | fail: | |
223 | return err; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Given a pointer to a lock, convert it to a ceph filelock | |
228 | */ | |
229 | int lock_to_ceph_filelock(struct file_lock *lock, | |
230 | struct ceph_filelock *cephlock) | |
231 | { | |
232 | int err = 0; | |
233 | ||
234 | cephlock->start = cpu_to_le64(lock->fl_start); | |
235 | cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); | |
236 | cephlock->client = cpu_to_le64(0); | |
237 | cephlock->pid = cpu_to_le64(lock->fl_pid); | |
238 | cephlock->pid_namespace = cpu_to_le64((u64)lock->fl_nspid); | |
239 | ||
240 | switch (lock->fl_type) { | |
241 | case F_RDLCK: | |
242 | cephlock->type = CEPH_LOCK_SHARED; | |
243 | break; | |
244 | case F_WRLCK: | |
245 | cephlock->type = CEPH_LOCK_EXCL; | |
246 | break; | |
247 | case F_UNLCK: | |
248 | cephlock->type = CEPH_LOCK_UNLOCK; | |
249 | break; | |
250 | default: | |
251 | dout("Have unknown lock type %d", lock->fl_type); | |
252 | err = -EINVAL; | |
253 | } | |
254 | ||
255 | return err; | |
256 | } |